System and method for food safety inspection

ABSTRACT

A system and a method for monitoring and inspecting food safety is disclosed. The system adopts insert and use concept that only requires an initial push on a button to begin its function. The system provides visual alert for different conditions if food products are in unsafe status. The system is pre-calibrated during manufacture without complicated or multi-step calibration or recalibration procedures during application. The system relies on modern surface-mount microprocessor technology that enables long-term calibration stability along with very low power consumption for extended battery life.

FIELD OF THE INVENTION

The present invention generally relates to temperature measurement and,more particularly, to food safety inspection.

BACKGROUND OF THE INVENTION

In food service industry, during the course of transferring productsfrom either cold storage or normal cooking status to some designatedplace, food safety is a big concern. Regulatory authority and the foodservice industry have established that potentially hazardous foodproducts maintained either below 40° F. or above 140° F. are generallysafe from the growth of potentially dangerous bacteria. Thus, thetemperature window roughly between 40° F. and 140° F. can be consideredto be a danger zone. To ensure food safety, a simple and effectiveinspection method for monitoring food temperature and then alerting iffood temperature is in a danger zone is desired.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide aneasy-to-use food inspection device and method that ensures thatpotentially hazardous food products are in safe status.

Another object of the present invention is to provide a visual alert ifthe potentially hazardous food products are in unsafe status so thatpeople are warned in time to adopt necessary measures to ensure foodsafety.

In accordance with one aspect of this invention, a system and method ofinspecting potentially hazardous food products adopts a simple andstraightforward insert and use concept that only requires an initialpush on a button to begin its function.

In accordance with another aspect of this invention, a system and methodof inspecting potentially hazardous food products provides differentvisual alerts for different conditions if the potentially hazardous foodis in the danger zone.

In accordance with a further aspect of this invention, a system andmethod of inspecting potentially hazardous food products ispre-calibrated during manufacture using sensitive thermistor temperaturesensors and thus can eliminate or reduce complicated or multi-stepcalibration or recalibration procedures during application.

In accordance with a yet further aspect of this invention, a system andmethod of inspecting potentially hazardous products relies onmicroprocessor technology that enables long-term calibration stabilityalong with very low power consumption for extended battery life.

The above and other objects, features, and advantages of the presentinvention will be apparent in the following detailed description of thepreferred embodiments of the present invention when read in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of one embodiment of a food safety inspection deviceaccording to the invention.

FIGS. 2( a) and 2(b) are flowcharts illustrating a method for theoperation of the food safety inspection device according to anembodiment of the invention.

FIG. 3 is a diagram of another embodiment of the food safety inspectiondevice according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a diagram of one embodiment of a food safety inspection device100 for ensuring that the potentially hazardous food products (referredto “foods” thereafter) are in safe condition, i.e., the foodtemperatures are either below a lower temperature threshold (e.g., about40° F.) or above a higher temperature threshold (e.g., about 140° F.). ,and providing a visual alert if the foods are in unsafe status, i.e.,the food temperatures fall between the lower temperature threshold(e.g., about 40° F.) and the higher temperature threshold (e.g., about140° F.), according to the invention.

It should be understood that the range of 40° F. to 140° F. is exemplaryonly, and that the device can be configured to operate according todifferent ranges without departing from the spirit and the scope of theinvention. For example, a range of 30° F. to 150° F., or any other rangesuitable to the application, could be used.

The food safety inspection device 100 includes a power source 110, atemperature sensor 120, a reset mechanism 130, a warning mechanism (140,or 150, or 140 and 150), and a processor 160.

The food safety inspection device 100 is powered by a power source 110,which supplies power to electronic components of the device. The powersource can be either a DC or an AC power supply. The DC power supply canbe any suitable commercial batteries available on the market.

The temperature sensor 120 is used as a medium to physically touch theinspected food and thus sense the temperature of the food. Of course,the sensor could be applied to physically touch a container holding thefood (a plat, a can, et.) in addition to or instead of physicallytouching the food. According to one approach, the temperature sensorconsists of a sensor tip and a thermistor which is physically located inthe sensor tip's sheath; the sensing tip is about 6 inches in length andmade up of stainless steel. Any suitable device for sensing or measuringtemperature could be used.

The reset mechanism 130 is used to reset the device so that ameasurement can be initiated. According to one approach, the resetmechanism can be made as a pushable button. Any other suitable mechanismfor resetting the device could be used, such as toggle switch, etc.

The warning mechanism (140, or 150, or 140 and 150) is used to provide awarning when the inspected food is in unsafe status. The warningmechanism can be either in audio or visual form, or both. The audio formcan be any indicium which can give off an audio warning such as beeping.The visual form can be any visual indicium which can give off a visualwarning (e.g., flashing) such as light emitting diodes and light bulbs,or other suitable device for providing a visual indicia. According toone approach, the device has one visual indicium which can flash a colorwhen alerting. According to another approach, the device has two visualindicia, when alerting, one giving off a red flashing warning 140corresponding to one condition and the other giving off a blue flashingwarning 150 corresponding to another condition.

The processor 160 is used to process measured data corresponding to thetemperature of the inspected food. According to one approach, theprocessor 160 determines whether the food temperature falls below thelower temperature threshold or exceeds the higher temperature threshold,determines whether the food temperature falls between the lowertemperature threshold and the higher temperature threshold, determinewhether the food temperature falls between the lower temperaturethreshold and the middle temperature setpoint, and determine whether thefood temperature falls between the middle temperature setpoint and thehigher temperature threshold. Preferably, the processor comprises amemory, internal registers, a clock, and outputs. According to oneembodiment, ATTiny13 AVR microprocessor is adopted. Other types ofprocessors or controller-type devices could easily be used.

FIG. 2( a) is a flowchart illustrating the operation of a food safetyinspection device with an audio indicium or one visual indicium as itswarning mechanism according to one embodiment of the invention. FIG. 2(b) is a flowchart illustrating the operation of the food safetyinspection device with two visual indicia as its warning mechanismaccording to another embodiment of the invention. The method of FIGS. 2a and 2 b is described in connection with FIG. 1 in order to set forththe method in a concrete fashion easily understood by the person ofordinary skill. However, this articulation of the method is exemplaryonly, and the method could be implemented using structures differentfrom that of FIG. 1.

The user of the device first connects or installs a power source beforethe device is ready to inspect food as set forth in step 210. The userthen places the temperature sensor of the device on or into the food sothat the temperature sensor physically touches the inspected food as perstep 220. According to step 230, a reset mechanism is pushed to initiatethe device. According to one approach, if the device uses an audioindicium as its warning mechanism, the device then beeps to indicatethat the device is measuring the temperature of the inspected food.According to another approach, if the device uses one visual indicium(or two visual indicia) as its warning mechanism, the visual indicium(or indicia) light(s) up for several seconds (e.g., about 2 seconds).

According to one embodiment (i.e., the device uses audio indicium), whenthe monitored food is cold (e.g., below about 40° F.). , such as meatjust taken out from a refrigerator, if the food safety inspection deviceis applied, the audio indicium remains off, which means the monitoredfood is in safe status and no safety action needs to be undertaken, asper steps 240 and 250. When the monitored food is hot (e.g., above 140°F.). , such as just-cooked soup, if the food safety inspection device isapplied, the audio indicium remains off, which represents the monitoredfood is also in safe status and no safety action needs to be undertaken,as per steps 240 and 250.

Similarly, according to another embodiment (i.e., the device uses onevisual indicium [or two visual indicia]), when the monitored food iscold (e.g., below about 40° F.). , if the food safety inspection deviceis applied, the visual warning indicium (or indicia) remains off, as persteps 240 and 250. When the monitored food is hot (e.g., above 140° F.)., if the food safety inspection device is applied, the visual warningindicium (indicia) remain off, as per steps 240 and 250.

When initially cold food is removed from cold storage and exposed to awarmer environment for certain period of time, e.g., a salad containeris taken out from a refrigerator and placed on a counter for laterserving, the temperature of the food gradually increases. Once thetemperature of the monitored food increases over a lower threshold(e.g., about 40° F.). , the audio indicium or visual indicium (orindicia) gives off a warning. According to one approach (i.e., thedevice uses an audio indicium), the device starts to beep until thereset mechanism is pushed, which indicates that the monitored food is onunsafe condition, as per step 260. According to another approach (i.e.,the device has one visual indicium), the device starts to flash in afast blinking mode until the reset mechanism is pushed, as per step 260.According to one further approach (i.e., the device has two visualindicia), the red visual indicium starts to flash until the resetmechanism is pushed, as per steps 270 and 280.

Likewise, when initially hot food is exposed to air for a while, e.g., ajust-cooked soup, the temperature of the food gradually decreases. Oncethe temperature of the monitored food decreases below the highertemperature threshold (e.g., about 140° F.). , the audio indicium orvisual indicium (or indicia) gives off warning. According to oneapproach (i.e., the device uses an audio indicium), the device starts tobeep until the reset mechanism is pushed, which indicates that themonitored food is on unsafe condition, as per step 260. According toanother approach (i.e., the device has one visual indicium), the devicestarts to flash until the reset mechanism is pushed, as per step 260.According to one further approach (i.e., the device has two visualindicia), the blue visual indicium starts to flash until the resetmechanism is pushed, as per steps 270 and 290.

If the temperature of the monitored food is around the middle oftemperature range between the lower temperature threshold (e.g., about40° F.) and the higher temperature threshold (e.g., about 140° F.). ,according to one embodiment (i.e., the device uses two visual indicia),the red indicium flashes when the monitored food is below a roughlymiddle temperature setpoint (e.g., about 90° F.) as per step 280, andthe blue indicium will flash when the monitored food is above theroughly middle temperature setpoint (e.g. about 90° F.) as per step 290.

The flash of the visual indicium can alert relevant personnel so thatsome action can be taken. For example, the temperature of the initiallyhot foods can be raised up above the higher temperature threshold (e.g.,about 140° F.). , or the temperature of the initially cold foods can belowered down below the lower temperature threshold (e.g., about 40° F.).Thus, the monitored foods can be monitored or returned to a safecondition. Of course, if the food is in unsafe status, the establishmentcan simply dispose of the food rather than returning it to a safetemperature.

FIG. 3 illustrates how a food safety inspection device measures thetemperature of the inspected food according to an embodiment of theinvention.

To initiate a measurement cycle, the output ports 170 and 180 are firstdriven low for a time period proportional to a time constant, where thetime constant is the product of the thermistor 120 resistance, R, andcapacitor's 310 capacitance, C. This allows enough time for thecapacitor, C, to fully discharge. Then both output ports 170 and 180 aredriven high, charging the capacitor through the thermistor's resistance.Once the capacitor becomes adequately charged, the transistor 320 turnson and pulls the output port 180 low. The time for the output port 180to be driven from high to low by the transistor 250 is a function ofR×C×Constant of the Circuit . Since the resistance, R, of the thermistoris related to temperature of the sensor, the time lapse is directlyrelated to the temperature. The processor's internal clock is used tomeasure this time lapse.

By means of a calibration procedure during manufacture, the time lapsesare calibrated to correspond to the designated temperatures, andprogrammed into the processor 160. By matching the measured time lapsewith the calibrated value stored in the processor 160, the processor 160can determine the actual temperature of the monitored food and thuswhether the food is in safe or unsafe status.

According to one embodiment, the processor can transmit the temperaturedata to a remote receiver at a designated interval to keep a record oftemperature history. The remote receiver could be any device which isable to receive, save, and display the transmitted data. The processorcould transmit the data through a wired connection (e.g., cables) orthrough a wireless connection (e.g., RF transmitter, etc.). The data canbe forwarded over a network (Internet, Intranet, etc.) to be monitoredand further evaluated.

One variation of the present invention is that the food safetyinspection device could be mounted on coolers. For example, when thecooler goes above 40° F., the device will flash a red light to alertpeople about the safety status of the foods in the cooler. Modificationof the sensor 120 may be appropriate for this application so that thesensor can be easily attached to the inner wall of the cooler. Thetemperature sensor 120 can be detached from the other components of thedevice so that the sensor is located inside the cooler and the othercomponents of the device are attached or located outside the cooler.

One further variation of the present invention is that the device isredesigned so that it can float in a bath tub when a mother prepares forbathing a baby. If the bath water is too hot (i.e., above some specifictemperature), the device will flash and alert the mother so that themother can adjust the bath temperature to ensure the comfort and safetyof the baby. This embodiment could be implemented using the basiccomponents of FIG. 1, and with the addition of some protective materialto waterproof the device and provide for buoyancy.

A specific embodiment of the food safety inspection device according tothe invention has been described for the purpose of illustrating themanner in which the invention may be made and used. It should beunderstood that implementation of other variations and modifications ofthe invention in its various aspects will be apparent to those skilledin the art and that the invention is not limited by the specificembodiment described. It is therefore contemplated to cover by thepresent invention any and all modifications, variations, or equivalentsthat fall within the true spirit and scope of the basic underlyingprinciples disclosed and claimed herein.

1. A device for evaluating food safety, comprising: a processor forprocessing measured data corresponding to the temperature of food,including determining whether the food temperature falls below a firsttemperature setpoint or exceeds a second temperature setpoint; anddetermining whether the food temperature falls between the firsttemperature setpoint and the second temperature setpoint; a memory forstoring data; a sensor for sensing data corresponding to the foodtemperature; and wherein the first temperature setpoint is lower thanthe second temperature setpoint;
 2. The device of claim 1, furthercomprising: two visual indicia for providing a visual alert; wherein thetwo visual indicia remain off when the food temperature is below thefirst temperature setpoint or above the second temperature setpoint; andwherein the two visual indicia provide a visual alert in differentcolors when the food temperature falls between the first temperaturesetpoint and the second temperature setpoint, one color for when thefood temperature is above the first temperature setpoint and below thethird temperature setpoint, and the other color for when the foodtemperature is below the second temperature setpoint and above the thirdtemperature setpoint.
 3. The device of claim 2, wherein the thirdtemperature setpoint is between the first temperature setpoint and thesecond temperature setpoint.
 4. The device of claim 1, furthercomprising: one visual indicium for providing a visual alert; whereinthe visual indicium remains off when the food temperature is below thefirst temperature setpoint and above the second temperature setpoint;and wherein the visual indicium provides a visual alert when the foodtemperature falls between the first temperature setpoint and the secondtemperature setpoint.
 5. The device of claim 1, further comprising asensing tip for providing a physical contact with the food.
 6. Thedevice of claim 1, further comprising means for resetting said device tostart or restart operation.
 7. The device of claim 1, further comprisingbatteries for supplying power to the device components.
 8. The device ofclaim 1, further comprising a remote receiver which receives, saves anddisplays the transmitted temperature data at a designated interval. 9.The device of claim 1, wherein the processor comprises registers, aclock, and outports.
 10. The device of claim 1, wherein the sensor iscalibrated during manufacture to establish the correspondingrelationship between the measured data and temperature.
 11. A method ofevaluating food safety, comprising: placing a sensor on the food so thatthe sensor physically touches the food; measuring data corresponding tothe food temperature by means of the sensor; and determining, by meansof the processor, whether the food temperature falls below the firsttemperature setpoint, or exceeds above the second temperature setpoint,or falls between the first temperature setpoint and the secondtemperature setpoint.
 12. The method of claim 11, further comprisingresetting said device to start or restart operation.
 13. The method ofclaim 11, further comprising: calibrating said device to establishcorresponding relationship between the measured data and temperature;and storing this relation in said device.
 14. The method of claim 11,further comprising providing no visual alert when the food temperatureis below the first temperature setpoint or above the second temperaturesetpoint.
 15. The method of claim 11, further comprising providing avisual alert, by means of one visual indicia, when the food temperaturefalls between the first temperature setpoint and the second temperaturesetpoint.
 16. The method of claim 11, further comprising providing avisual alert of one color, by means of one visual indicium, when thefood temperature is above the first temperature setpoint and below thethird temperature setpoint; and providing a visual alert of the othercolor, by means of the other visual indicium, when the food temperatureis below the second temperature setpoint and above the third temperaturesetpoint.
 17. The method of claim 11, further comprising receiving,saving, and displaying the measured temperature data at a designatedinterval by means of a remote receiver.